Replacing Host Subsystem Components; Taking The Host Subsystem Offline; Replacing An Scb; Figure 42: Installing The Air Filter In An Mx240 Router - Juniper MX240 Hardware Manual

MX240 Ethernet Services Router Hardware Guide

Figure 42: Installing the Air Filter in an MX240 Router

Replacing Host Subsystem Components

To replace a host subsystem, use the following procedures:

Taking the Host Subsystem Offline

The host subsystem is taken offline and brought online as a unit. Before you replace
an SCB or a Routing Engine, you must take the host subsystem offline. The host
subsystem is hot-pluggable.
If the router has only one host subsystem, taking the host subsystem offline causes
the router to shut down.
Normally, if two host subsystems are installed in the router,
master and
(or either of its components) without interrupting the functioning of the router. If
you take the master host subsystem offline, the backup host subsystem becomes
the master (the router might reboot, depending on your configuration). The effect
of taking the master host subsystem varies depending on your configuration of high
availability features.
High availability features include Routing Engine redundancy, graceful Routing Engine
switchover (GRES), nonstop bridging, nonstop active routing, graceful restart for
routing protocols, Virtual Router Redundancy Protocol (VRRP), and unified in-service
software upgrade (ISSU). Some high availability features are not supported by all
platforms and all PICs. For information about the first supported JUNOS release for
these features by PIC and platform, see the JUNOS High Availability Configuration
Guide.
To take a host subsystem offline:
96

Replacing Host Subsystem Components

Taking the Host Subsystem Offline on page 96
Replacing an SCB on page 97
functions as the backup. You can remove the backup host subsystem
RE1
functions as the
RE0